In 'The Triple Agent,' Joby Warrick offers a compelling narrative of the 2009 suicide bombing on a CIA base in Afghanistan by a purported informant who was actually an Al Qaeda operative.

In the afternoon of Dec. 30, 2009, a meek Jordanian doctor who had gained access to the top commanders of Al Qaeda was driven onto a secret CIA base at Khost in eastern Afghanistan for his first formal debriefing. More than a dozen CIA officers and other Americans stood in a receiving line to welcome the so-called "golden source." Camp cooks had even baked him a celebratory cake.

Until then, no American had ever met the star informant, and only a handful even knew his name: Humam al-Balawi.

But he was deemed so pivotal to America's war on Al Qaeda that back in Washington, President Obama had been notified and was awaiting news of the meeting.

Balawi instead detonated a powerful bomb sewn into his vest, shooting a shower of lethal shrapnel through metal and bone. The explosion killed seven CIA officers, a Jordanian intelligence officer who was a member of the royal family, a CIA-trained Afghan driver, and the suicide bomber himself. The CIA had not lost that many operatives in a single day since the bombing of the U.S. Embassy in Beirut in 1983, which killed eight CIA officers.

Who was the seemingly mild-mannered doctor, and why was he escorted onto a fortified CIA base, deep inside a U.S. military compound, without being searched? Why were so many CIA officers, far more than usual, waiting for him? Why did events go so tragically wrong?

Joby Warrick largely answers those questions in "The Triple Agent," a disturbing narrative of the events leading to that awful day. Warrick is a brilliant reporter and a fine writer. If newspapers are the first draft of history, he has written a compelling and complete second draft in surprisingly short order. This is as gripping a true-life spy saga as I've read in years.

Still, at just more than 200 pages of text, the book comes off at times as a hurried snapshot more than a nuanced portrait. There is too little context or history, and several minor errors, sometimes breathless prose and repetitive passages don't help. But there are jewels here, including startling claims about the CIA's covert drone war in Pakistan.

"The agency's Predators could put a missile through the window of a moving car or nail a target the size of a dinner plate in a narrow alley at night without harming buildings on either side," Warrick writes. "The aircraft's operators could — and, on at least one occasion did — change a missile's trajectory in midflight to avoid an unintended target that suddenly wandered into its path."

Inevitably, the main characters are troubled. The CIA base chief, Jessica Matthews, had spent only three months in Afghanistan. She was a hard-charging Al Qaeda expert back home, and played a role in the water-boarding of a terror suspect. But she had never served in a war zone, run a surveillance operation or handled an informant. And she was desperate to erase a stain on her record: An internal report had named her as one of the CIA managers who bore responsibility for bungling intelligence before the Sept. 11 attacks.

Balawi, the Jordanian physician, secretly penned anti-American screeds on jihadist websites under a nom de guerre, Abu Dujana al-Kurorasani. Arrested by Jordanian intelligence in early 2009, he abruptly switched sides. He offered to go to the lawless tribal regions of Pakistan to help the CIA penetrate Al Qaeda. He would become a double agent.

Balawi soon sent his Jordanian handler a short but remarkable video file. It showed him meeting an Islamic scholar who was known to be one of Osama bin Laden's closest associates. Weeks later, the doctor sent word that he had a new medical patient: Ayman al Zawahiri, then Bin Laden's top deputy and today his successor as chief of Al Qaeda.

At the CIA, which has struggled to infiltrate Al Qaeda, the grainy video was "one hundred megabytes of flash and sizzle," Warrick writes. But news that a mole was in direct contact with Zawahiri, the terrorist leader who had helped dream up the Sept. 11 attacks, was rushed to the White House. "From Kabul to Amman to Langley, marble buildings seemed to shift on their foundations."

It was, sadly, too good to be true. Balawi had no training as a spy and had not been vetted as an informant. The two intelligence officers who knew him best — his Jordanian handler, and the CIA case officer — both expressed doubts. They were right: Balawi had become a triple agent.

He had offered his services to Al Qaeda, and they would use him as revenge for the CIA drone attacks. He recorded several jihadist videos in the days before he blew himself up, and he delivered his final message in English to ensure the widest audience. "We will get you, CIA team," he vowed. "This is my goal: to kill you.... And you will be sent to hell."

After the bombing, an internal CIA investigation concluded that no single U.S. intelligence officer was to blame. But just as in the Sept. 11 attacks, "managers at every level were blinded to warnings and problems that would seem screamingly obvious in hindsight," Warrick writes. The problem was "the eagerness of war weary spies who saw a mirage and desperately wanted it to be real."

The terrorist leader who had organized Balawi's suicide mission was more precise. In an Internet posting, Sheikh Saeed al Masri called Al Qaeda's penetration of a guarded CIA base a model of "patience, good planning and management." Unfortunately, Warrick makes clear, that was exactly where the CIA failed when they waited in line to greet Balawi.